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Xnke

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Everything posted by Xnke

  1. Might look into FJ24 rods before you relagate them to non-stock....technically they were stock too, and are the basis of some mighty fine "stock" rods... At 600hp, the rods can start to show cracking across the beam near the small end. it isn't immediate, but there isn't much time at that level before rod failure occurs.
  2. I have used that method during my experimentation with the Mahle cam-in-cam method of VVT, there were oiling and mechanical issues unresolved there. never ran one...but it LOOKED pretty awesome.
  3. It'll run fine. "Spool time" will suffer a little, but you will make more power on the top end than a smaller cam. You should see 270-300RWHP at 14lbs once the ECU is dialed in, but I would not expect full boost until 3000-3200RPM. The problem with 54* of overlap is that you will loose some idle vacuum, so the power brakes will be weaker. It will be a little soft under 3000RPM, but the cam will come on about then, and then you'll spin up the compressor so then your boost comes in right behind it...expect a big push. Hope you don't intend to use the stock ecu with that cam, however...
  4. When I say rod bolts...I mean throw the old rod bolts out and replace them with aftermarket units. The stock rod bolts are the only major weak point I can think of in the stock L28 bottom end...and they are CHEAP!
  5. Don Devendorf, prior to switching to the sports option rods. The stock rods didn't last long enough between races, and took too much time to prep. Tony...I said 1000+HP and 9500+RPM...I didn't mean to imply that they did both at the same time. I see now how that could have been construed; I do not know of anyone pushing both of those numbers at the same time. I have seen prepped stock rods spin 12,500RPM in an L18, for limited use, but that's about the fastest I've seen them turned. That particular engine now has sintered titanium alloy rods installed...some ridiculous exotic that I don't even want to think about the cost of.
  6. I have a set of partially finished patterns and core boxes for the L6. I started down that road, but haven't finished, 7 years later.
  7. The stock rods have been run in racing service, prepped and checked, at 1000hp+ and 9500rpm+. The rod bolts, however, will need attention. At the 400hp level, the stock rods, checked for flaws, will be just fine when installed with good rod bolts.
  8. To me, it really looks like they locate with a single hollow dowel on the outside cam tower bolt...is that really all they locate with? Honda guys seem to have no trouble pulling and placing the cam towers, so I think Tony is got the idea, using a mandrel to align them.
  9. Why line bore them? Are they split caps? If not split caps, jig bore them. You have CNC capabilities...there is no need to line-bore the cam towers if you can repeatably set up sets of cam towers in a jig designed to hold them all on a plane during the boring. The cam towers bolt to the head. If the cam towers are uniform, and the top face of the cylinder head is uniform, then the existing bores will be uniform. Just like removing and replacing the cam towers on a standard L6 head. They could have been done by bolting to a jig, line boring or jig boring, removed from that jig, and placed onto the milled-flat, dowel pin aligned surface of the cylinder head, and would STILL be in alignment. Don't make it harder than it has to be! Oh, and the ITBs...they're not hard on N/A engines! I will gladly make a drive if you need/want help tuning them.
  10. Make it 2" thick, steel. same specs as an RB26 torque plate.
  11. That looks like ring scuffing at the top of the bore...but then it doesn't look like ring scuffing because it is ONLY at the top of the bore. What are the current piston ring gaps, and are they ITM piston rings?
  12. I am going to bring it up again...make sure you can get the cam lobes hard enough. You're looking in the RC50 range...can your guys heat treat a 4140 cam to that level without making it so brittle it breaks under the spring load? Roller cam profiles RAPIDLY ramp up spring pressures when you start getting bigger.
  13. That photo was taken in January, I believe. And yes, it's pronounceable...many people have no issues with it. That intake didn't clear the hood by about 3/4". It also is 22" long, so the shorter LD intake plenum should clear fine.
  14. Good luck getting anyone from the world of Honduh to consider making a custom cam core...The only one I'd even bother to recommend is Dave at Crower Cams and Equipment...NOT the same as Brian Crower of honda/SR20 fame. Dave will do it for you, no problem Also, Mike Jones of Jones camshaft can do the job. He's not cheap, but you WILL win races.
  15. 4140 isn't what I had luck with for that... Cast cores with hardfacing didn't last. Been there, 4130, 4340, neither. They don't have the durability, didn't hold up for me. I went with 8620 deep-cased after a "pre-grind", followed up with a final grind, and that so far has lived. I doubt that this is going to be required, though, I was spinning a 0.620" lift 310* seat duration, 280* duration at 0.200" lift roller profile. Springs are a smidge stiff in that N42 head...you won't take them out without specific tools. How are the Honda cores made? Maybe remelt and cast from those? They'll have the proper metallurgy, and you have an example to harden to spec. G-E, an unhardened cam will NOT live at all in the roller environment. It will begin to break down VERY fast. Derek, Look at the hardness of the cam followers and go within 6RC, but no closer than 3RC on the hardness.
  16. MG SU's and Datsun SU's are not exactly the same. Close, but not exactly the same and so MG tuning guides will be a little "off". Turn the nuts all the way in, then two and a half full turns out. The nuts are knurled and have big and small "dot" marks. Use the stock needles and make sure they are in sync at idle and at 1500RPM, and that you do not have air leaks. Air leaks in the carb body are very common. Use a stock replacement mechanical pump, and a stock fuel rail...you will not need a regulator and it will provide proper fueling. It's that easy. Often times electric low-pressure pumps and regulators don't work out well on these cars...be it because of wrong/poor/sloppy installs or that it just doesn't work out well, I don't know...but many posts here that deal with SU carbs and not-stock fuel rails or fuel pumps are resolved with "stock parts". As far as smoke on the manifold, white smoke is generally going to be coolant. it may actually be burning glycol in the chamber or steam rising off an external leak. Oil/grease/fuel generally will be blue/black smoke, so you can probably rule those out. Take the radiator cap off and make sure you're not loosing coolant. Run the cold engine with the cap off, see if it bubbles from cold...if so, likely BHG.
  17. AT THE FRONT OF THE ROCKER COVER. The hood slopes down, you will have no issues except for the front corner.
  18. I don't know. Is Atsugi the OEM supplier? Mine have the Hitachi mark. The only Atsugi/Paraut rockers I have here are obvious replacements, as none of my engines ever came with a full set of them.
  19. Chequered Flag has 39 spline stubs and mating flanges, and I bet Joe can drill a set for 5-lug.
  20. Realize that every single vaccum line, hose, and widget on the stock intake goes to SOMETHING on the stock computer. Remove them at your own discretion...but remember where they went so when the car does not run right, you can put it back....
  21. To the top of the front of the rocker cover minus 1". Ask me how I know.
  22. The RedlineMotorsports is an Atsugi rocker...Which makes sense, Atsugi owns/operates/somethign Paraut.
  23. Just because it was run here as a solid lifter 1981-ish turbo cam, doesn't mean it wasn't used in other markets in other cars. Also might just be a replacement cam!
  24. "$wget -mR http://forums.hybridz.org/topic/119641-twin-cam-head-for-the-l6-from-derek-at-datsunworks/page-1?do=findComment&comment=1121013 && http://forums.hybridz.org/topic/119641-twin-cam-head-for-the-l6-from-derek-at-datsunworks/page-2?do=findComment&comment=1121013 && http://forums.hybridz.org/topic/119641-twin-cam-head-for-the-l6-from-derek-at-datsunworks/page-3?do=findComment&comment=1121013" Fixed that bit for ya.
  25. Heh, I can't believe I was hand-finishing rockers at that price then. That's a LOT of work! Reground Nissan rockers have been what I use and will continue to use, as they LAST. I've not had good luck with aftermarket parts...even the Atsugi Japan rockers I have showed significantly more wear than the Nissan rockers from the same engine.
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